Members of Congress are welcoming the Bush administration's decision to support a two-month extension of the work of an independent commission investigating the September 2001 terrorist attacks in the United States. But some lawmakers say the commission needs even more time.

Word of the president's decision was announced by White House spokesman Scott McClellan.

He said Mr. Bush now supports a 60-day extension of the original 18 month work period Congress approved for what is called the 9-11 Commission.

Mr. McClellan was asked to explain why the administration suddenly dropped opposition to the commission's requests for more time. "The commission came to us, said they believe they need some additional time to do the job that they want to do. And we were glad to discuss that with the commission. But again, we continue to believe they should move forward as quickly as possible, to do a thorough job and get their work done in a timely manner," he said.

The extension would push a deadline for completion of the commission's work from May to July.

This is the second shift in position regarding investigations relating to the September 2001 terrorist attacks, and Iraq.

President Bush previously announced he would appoint a bi-partisan commission to investigate how intelligence on Iraqi weapons of mass destruction was handled before U.S. and coalition military action to oust Saddam Hussein.

The administration had opposed extending the work of the 9-11 Commission, with some critics suggesting Mr. Bush felt members of the commission were politically biased and that information could be used by opposition Democrats in an election year.

Commission members had complained about difficulty in obtaining certain classified information they had sought from the White House.

Mr. McClellan again rejected allegations that the administration has been deliberately making it hard for the commission to do its work. "We have worked very cooperatively and closely with the chairman and vice chairman and others on the commission to help them move forward quickly to get this job done. It's very important work. The president strongly supports the work of the commission, and we want to make sure it has all the information they need to complete their work," he said.

However, some Republicans have joined Democrats in urging that the commission be given even more time.

On Capitol Hill, Democratic and Republican members of the House held a news conference to announce legislation seeking to formally extend the commission's work until January 2005.

Vito Fossella, a Republican from New York, said, "If the commission feels in good faith that it needs more time to complete its work, to ensure another attack like September 11 never happens again, it would really border on irresponsible if we don't do that."

President Bush initially opposed formation of the 10-member commission which has an equal number of Democrats and Republicans. Congress eventually approved it, after the White House dropped its objection.

Preliminary details of the commission's reports, released in a recent hearing, showed that weaknesses in airline and airport security, as well as immigration, enabled the 19 hijackers to enter the country and hijack commercial airliners that were crashed into buildings in New York City and the Pentagon.